Meeting Abstract

P3.26  Thursday, Jan. 6  Invasive crab salinity preference: effects of acclimation and implications for estuarine distribution HUDSON, DM*; SEXTON, DJ; WINT, D; CRIVELLO, JF; University of Connecticut; Georgia State University; University of Connecticut; University of Connecticut david.hudson@uconn.edu

In areas where it has invaded, the shore crab Hemigrapsus sanguineus has become ubiquitous in the rocky intertidal zone of the Western North Atlantic, restricting its competitor, Carcinus maenas, to the subtidal. Itself an invader, C. maenas is still present in the intertidal zone along its invasion front in northern Canada and in its native range in Europe. A possibility for this pattern is that H. sanguineus hypoosmoregulates and as such is more likely to adequately defend shelter within the mid and upper intertidal. Since H. sanguineus shows low mortality across a broad range of salinities, we hypothesize that it will be behaviorally indifferent when presented with a choice of salinities, regardless of acclimation salinity of 5 ppt or 35 ppt. Initial results show preference to exist when a greater difference in salinities are presented, but indifference as the choice gradient is lowered. This implies a hardiness for rapid changes in salinities which happen in the intertidal zone, enhancing their competitiveness as an invader, and partially explaining its dominance in this habitat type.